Starting and unloading device



F. B. THOMAS.

STARTING AND UNLOADINYG DEVICE.

APPLICAHON FILED HOV-13,1919.

1,422,902, Patefited July 18,1922.

2 SHEETS-SHEET I.

- INVENTOR FRANK aTHoMAs ATTORNEY THOMAS.

Patented July 18, 1922 2 SHEETS-SHEET 2.

summs AND UNLOADING DEVICE.

, APPLICATION FILED NOV-13,1919- 1,422,902.

| "un 55 '1 1 24 z 54 l H i I 4 \H 1 w" 'IN\VIENTOR FRANK B.THOMAS %c// ATTORNEY U IT FRANK B. rues/ms, or WILKINSBURG, PENNSYLVANIA, AssIeNon fro 'rnn'wnsrma- Horsn am r ooNraNY, or WILMERDING, PENNSYLVANIA, A oonroaa'rIoN 0F PENNSYLVANIA.

.sran'rrNe AND nNnoanrNe nnvrcr.

asagna.

Specification of Letters Patent.

Patented July 13, 1922.

7 Application fil ed ltoveinber 13, 1913. Serial No 837,717.

and Unloading Devices, of which the follow ing is a-specification. i This invention relates tostarting and unloading devices, and more particularly to an internal combustion engine starting and a fluid compressor unloading equipment.

.Where an internal combustion engine is employed for driving a fluid compressor and the compressor is directly connected to the engine, if an electric starting motor is employed for starting the engine, it may happen that the compressor will be under load when the circuit of the motor is closed for starting the engine, in which case, the motor may fail to start the engine, due to-the fact that the motor must then operate the loaded compressor as well as start the engine.

The principal object of my invention is to overcome the above difliculty, by providing means for unloading the compressor upon operating the starting motor of the engine.

In the accompanying drawing; F ig. 1 is a sectional view of a' starting and unloading equipment embodying my invention; Fig. 2'

a wiring diagram of the electric circuits; and Fig. 3 a diagrammatic view of the complete system.

As illustrated diagrammatically in Fig. 3, the system includes a starting motor 31, operatively connected to the main shaft 5 1 of an internal combustion engine 55, the shaft 54 being direct connected to the fluid com-- pressor 24:. a I

The starting and unloading equipment, as shown in the drawing, comprlses a compressor governor device 1, an unloading de vice 2, a reservoir 3, into which the compressor 56 compresses fluid, an electric switch device 4, a magnet valve device 5, and a timing valve device 6, having a timing reservoir 7 connected thereto.

The compressor governor 1 may comprise a casing having piston chambers 8 and '9, containing pistons 10 and 11 which are connected by piston rod '12 for operating a slide valve 13, the valve chamber 14: containing said valve being connected to the reservoir 3.

F or varying the fluid pressure in piston chamber-8, a,valve 15 is provided, which is adapted to be operatedby a diaphragm 16, subject on one side to the pressure of an adjustable spring 17, and on the opposite side to-the' pressure in reservoir 3. i

. -F or varying the fluid pressure in piston chamber 9, a valve 18 is provided, which is adapted to be operated by a diaphragm 19, subject on one side to the pressure of an adjustable spring 20 and on the opposite side to the pressure in reservoir 3:

The unloading device-2 may comprise a piston 21 having a stem 22 for operating the usual suction or inlet valve 23 of the compressor 24 and the'fluid pressure on one side of said piston is controlled by slide valve 13.

The electric switch device 1 may comprise a casing having a piston chamber 25', containing a piston 26, having a piston stem 27 carrying movable contacts 28, adapted to engage fixed contacts 29, for controlling an electric circuit 30, including an engine starting motor 31 and a source of current 32.

The admission and release of fluid under pressure to and from the piston chamber 25 is controlled by the magnet valve device 5,

which may comprise a magnet 33, located in r a shunt circuit 34, with the source of current 32, and valves 35 and 36 adapted .to be controlled by'said magnet.

Fluid under pressure is supplied to and released from piston chamber 25 through- In operation, if the pressure of fluid in the reservoir 3 is'less than the cutting out pressure at which the governor 1 is adjusted,

the parts of the governor will be in the positions shown in Fig. 1, since the diaphragm 19 will then be operated by the spring 20 to permit the valve 18 to remain in open position, in which position, fluid is vented from piston chamber 9, while the valve 15 will bev held closed, because the pressure of spring 17 exceeds the pressure of fluid from reservoir 3, acting on diaphragm 16 sothat there is fluid under pressure in piston chamber 8, due to equalization of fluid through piston 10.

With the S arting switch 40 in open position, as shown in Fig. 2, the magnet 33 will be deenergiz ed, so that valve 35 will be with fluid under pressure and when the pressure has been raised to a predetermined degree, the valve piston 38 will be operated to open communication from pipe 37'- to' piston chamber 25.

The piston 26 "is then actuated to move the contacts 28 out of engagement with the contacts 29 and thus open the starting motor circuit.

If it is. desired to start the internal combustion engine, the switch 40 is closed and the magnet 33 is thus energized, but the circuit 30 of the starting; motor 31 is still held open by the switch device 4.

The magnet 33 being energized, the valve 36 will be closed and valve 35 opened, so as to vent fluid from piston chamber 8, through passage 45, past check valve 46 and past the valve 35 to the. atmospheric exhaust port 47.

The area of piston 10 being greater than the area of piston 9, the fluid pressure in chamber 14-, acting on the differential area of piston 10 will shift the pistons and slide valve 13, so that fluid under pressure is supplied from valve chamber 14 through passage 48 to piston 21, which is then actuated to open the inlet valve 23 of the fluid compressor, thus unloading the compressor.

At the same time fluid is vented from the timing reservoir 7, through pipe 37 and the restricted port, past the valve 35, to the exhaust port'47,

The restricted port 49 and the volume of reservoir 7 is such that after a predetermined time interval, ample to ensure the previous operation of the unloading piston 21, the pressure will be reduced sufficiently to permit piston 38 to be shifted, to its lower seat by spring 39, so that fluid is vented from piston chamb'er25 to exhaust port 50 and piston 26 is operated by spring 51 to cause the contacts 28 to close the circuit 30.

The starting motor 31 is then energized to effect the starting of the engine, with the compressor unloaded.

As soon as the engine is started, the switch 40 maybe opened, so as to stop the starting motor 31 and at the same time the magnet 33 is deenergized, thus causing the valve 35 to be seated and the valve 36 to be opened.

The exhaust from piston chamber 8 being cut off by the closing of valve 35, fluid pressure equalizes from valve chamber 14 through the piston 10 to piston chamber 8, causing the parts to move, so that slide valve 13 connectspassage 48 through cavity 52 with exhaust port 53. Fluid is thereupon vented from piston 21, permitting the inlet valve 23 to close, so that the compressor will operate- .7, and when'the pressure therein has been increased to a predetermined degree, the valve piston 38 is lifted to permit the flow of fluid under pressure to iston chamber 25. Piston 26 is then actuate to open the startin motor circuit 30.-

During the time that the engine is operat- I ing the compressor, the governor 1, operates to cut the compressor into and out of operation, so far as compressing fluid is concerned, by operating the unloading device 2.

As the pressure in reservoir 3 increases by the operation of the compressor, a point is reached where the pressure is suflicient to overcome the pressure of spring 20, so that diaphragm 19 is operated to close valve 18, and when the pressure has been increased to the cutting out point, the diaphragm 16 operates to opelr valve 15, so that fluid is vented from piston chamber 8, and the pistons 10 and 11 then operate to shift slide valve 13, so as to open passage 48, for supplying fluid to piston 21. Said piston then operates to open valve 23 and thereby unload the compressor.

.When the pressure in reservoir 3 becomes reduced, the valve 15 first closes and at a predetermined reduction in pressure the valve 18 is opened, so as to vent fluid from piston chamber 9 and thereby eflect the movement of the pistons 10 and 11 and slide valve 13. Piston 21 then moves so as to allow the valve 23 to seat and thereby cause the compressor to compress fluid into the reservoir 3.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is

1.111 a starting and unloading apparatus for aninternal combustion engine driven fluid compressor, the combination with a motor for starting the engine, of a device for unloading the compressor, a switch device for controlling the motor circuit, and means for operating said device to eflect the unloading of the compressor and for then operating said switch device to close the motor circuit.

2. The combination with a load adapted to be driven by an internal combustion engine, of an electric motor for starting said engine, an unloading device for relieving the engine of its load, a switch device for controlling the motor circuit, means for operating said unloading device and said switch device, and a timing means for delaying the operation of said switch device.

3. The combination with a load adapted to be driven by an internal combustion engine, of an electric motor for starting said lee engine, an unloading device operated by fluid under pressure for controlling the load on the engine, an electric switch -device operated by fluid under pressure for controlling the motor circuit, means for. controlling the fluid pressure for operating said unloading device and said switch device, and timing mechanism for delaying the operation of said switch device. i y

4. The combination with a motor forstarting an internal combustion engine andafluid compressor adapted to be driven by said engine, of a fluid pressure operated switch variations in fluid pressure for eflecting the operation of said unloading device, a fluid pressure operated switch device for controlling the motor circuit, a timing reservoir, a valve device operated according to the pressure in said. timing reservoir for supplying and releasing fluid under pressure to and from said switch device, and magnet controlled valve means for varying the fluid pressure on said valve mechanism and in said timing reservoir.

.6. The combination with an internal combustion engine, a load imposing member operatively connected to said engine, and a starting motor for the engine, of a device for relieving the engine ofthe load imposed by said member, a switch for controlling the motor circuit, and means for first operating said device to relieve the engine of its load and for then operating said switch to close the motor circuit.

In testimony whereof I have hereunto set my hand.

FRANK B. THOMAS. 

